1. Field of the Invention
The present invention relates to a retention mechanism for an electronic assembly.
2. Background Information
Integrated circuits are typically assembled into packages that are mounted to a printed circuit board. The printed circuit board may have a plurality of contact pads which plug into a mating connector. The mating connector may be mounted to a motherboard of a computer system. The contact pads must be aligned with corresponding contacts of the connector to properly connect the printed circuit board with the motherboard. Plugging the circuit board into the motherboard connector is typically a manual process which requires a certain level of skill to align the pads and contacts of the connector.
Some computer systems contain mechanical guide rails which receive the edges of the printed circuit board and align the pads with the contacts when the board is being plugged into the connector. The circuit board must be plugged into the connector in the correct orientation to properly operate within a computer system. It is therefore desirable to provide a keying feature which will insure that the circuit board is always plugged into the motherboard connector in the proper orientation.
Computer systems are sometimes exposed to shock and vibration loads. The shock and vibration loads create stresses in the printed circuit board and the motherboard connector. The guide rails are typically mounted to a metal frame of a computer which provides structural support for the circuit board and the connector. Some computer systems incorporate mechanical latches to secure the printed circuit board to the motherboard. The latches typically cooperate with the guide rail or other feature of the computer chassis.
The dimensional tolerances of the assembly must be kept within certain limits to insure that the latches are properly aligned and operable. Restrictive tolerances can increase the cost of producing the assembly. Additionally, the latches may increase the overall height of the assembly. It would be desirable to provide a retention mechanism which can secure a printed circuit board assembly to a motherboard while minimizing the height of the assembly and not requiring undesirable tolerances for the assembly components.
The integrated circuit within the package may be a microprocessor which contains millions of transistors that switch states at a very high frequency. The high speed processors may emit electro-magnetic interference (EMI) which may produce electrical noise within the computer system. It would be desirable to provide an electrical assembly that reduces the amount of EMI that is transmitted from an integrated circuit.